There is a need for improved orthodontic and dental appliances capable of facilitating orthodontic tooth movements, stabilizing tooth positions or protecting teeth from potentially damaging outside forces. Existing materials and products are constructed from single layer materials, bi-layer materials or tri-layer materials which have limited functionality and may suffer from performance deficiencies. Aligners are plastic shells which fit over teeth designed to apply translational or rotational forces to teeth. Their ability to accurately move teeth is limited by their effective modulus, elasticity and ability to resist creep and stress relaxation. Additionally, they generally should be resistant to staining and environmental stress cracking.
Appliances for protection of teeth, for example, sports mouth guards, and dental splints have contradictory requirements. On the one hand, they should be capable of dissipating impact forces and on the other hand should be thin and not interfere with the natural occlusion of a person's teeth or impede speaking.